/*

     File: AVSEViewController.m

 Abstract: The players UIViewController class. It sets up the AVPlayer, AVPlayerLayer, manages adjusting the playback rate, enables and disables UI elements as appropriate and handles the AVMutableComposition, AVMutableVideoComposition, AVMutableAudioMix items across different edits 

  Version: 1.1

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 */

#import "AVSEViewController.h"

#define kTrimIndex 0

#define kRotateIndex 1

#define kCropIndex 2

#define kAddMusicIndex 3

#define kAddWatermarkIndex 4

#define kExportIndex 0

@interface AVSEViewController ()

- (void)setUpPlaybackOfAsset:(AVAsset *)asset withKeys:(NSArray *)keys;

- (void)stopLoadingAnimationAndHandleError:(NSError *)error;

@end

static void *AVSEPlayerItemStatusContext = &AVSEPlayerItemStatusContext;

static void *AVSEPlayerLayerReadyForDisplay = &AVSEPlayerLayerReadyForDisplay;

@implementation AVSEViewController

#pragma mark - View Controls

- (void)viewDidLoad

{

    [super viewDidLoad];

    [self.playerView setBackgroundColor:[UIColor blackColor]];

    [[self view] addSubview:self.playerView];

    [[self playerView] addSubview:self.exportProgressView];

    [[self view] setAutoresizesSubviews:YES];

    [[self playerView] setAutoresizesSubviews:YES];

    [[self loadingSpinner] setHidden:YES];

    [[self exportButton] setEnabled:NO];

    // Create a AVAsset for the given video from the main bundle

    NSString *videoURL = [[NSBundle mainBundle] pathForResource:@"Movie" ofType:@"m4v"];

    AVAsset *asset = [[AVURLAsset alloc] initWithURL:[NSURL fileURLWithPath:videoURL] options:nil];

    // Load the values of AVAsset keys to inspect subsequently

    NSArray *assetKeysToLoadAndTest = @[@"playable", @"composable", @"tracks", @"duration"];

    // Tells the asset to load the values of any of the specified keys that are not already loaded.

    [asset loadValuesAsynchronouslyForKeys:assetKeysToLoadAndTest completionHandler:

     ^{

         dispatch_async( dispatch_get_main_queue(),

                        ^{

                            // IMPORTANT: Must dispatch to main queue in order to operate on the AVPlayer and AVPlayerItem.

                            [self setUpPlaybackOfAsset:asset withKeys:assetKeysToLoadAndTest];

                        });

     }];

    self.inputAsset = asset;

    // Create AVPlayer, add rate and status observers

    [self setPlayer:[[AVPlayer alloc] init]];

    [self addObserver:self forKeyPath:@"player.currentItem.status" options:NSKeyValueObservingOptionNew context:AVSEPlayerItemStatusContext];

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(editCommandCompletionNotificationReceiver:)

                                                 name:AVSEEditCommandCompletionNotification

                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(exportCommandCompletionNotificationReceiver:)

                                                 name:AVSEExportCommandCompletionNotification

                                               object:nil];

}

-(NSUInteger)supportedInterfaceOrientations

{

    return UIInterfaceOrientationMaskAll;

}

- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration

{

    if (self.playerView) {

        [self updatePlayerLayerSize];

    }

}

#pragma mark - Playback

- (void)setUpPlaybackOfAsset:(AVAsset *)asset withKeys:(NSArray *)keys

{

    // This method is called when AVAsset has completed loading the specified array of keys.

    // playback of the asset is set up here.

    // Check whether the values of each of the keys we need has been successfully loaded.

    for (NSString *key in keys) {

        NSError *error = nil;

        if ([asset statusOfValueForKey:key error:&error] == AVKeyValueStatusFailed) {

            [self stopLoadingAnimationAndHandleError:error];

            return;

        }

    }

    if (![asset isPlayable]) {

        // Asset cannot be played. Display the "Unplayable Asset" label.

        [self stopLoadingAnimationAndHandleError:nil];

        [[self unplayableLabel] setHidden:NO];

        return;

    }

    if (![asset isComposable]) {

        // Asset cannot be used to create a composition (e.g. it may have protected content).

        [self stopLoadingAnimationAndHandleError:nil];

        [[self protectedVideoLabel] setHidden:NO];

        return;

    }

    // Set up an AVPlayerLayer

    if ([[asset tracksWithMediaType:AVMediaTypeVideo] count] != 0) {

        // Create an AVPlayerLayer and add it to the player view if there is video, but hide it until it's ready for display

        AVPlayerLayer *newPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:[self player]];

        [newPlayerLayer setFrame:[[[self playerView] layer] bounds]];

        [newPlayerLayer setHidden:YES];

        [[[self playerView] layer] addSublayer:newPlayerLayer];

        [self setPlayerLayer:newPlayerLayer];

        [self addObserver:self forKeyPath:@"playerLayer.readyForDisplay" options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew context:AVSEPlayerLayerReadyForDisplay];

    }

    else {

        // This asset has no video tracks. Show the "No Video" label.

        [self stopLoadingAnimationAndHandleError:nil];

        [[self noVideoLabel] setHidden:NO];

    }

    // Create a new AVPlayerItem and make it the player's current item.

    AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:asset];

    [[self player] replaceCurrentItemWithPlayerItem:playerItem];

}

- (void)stopLoadingAnimationAndHandleError:(NSError *)error

{

    [[self loadingSpinner] stopAnimating];

    [[self loadingSpinner] setHidden:YES];

    if (error) {

        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:[error localizedDescription]

                                                            message:[error localizedFailureReason]

                                                           delegate:nil

                                                  cancelButtonTitle:@"OK"

                                                  otherButtonTitles:nil];

        [alertView show];

    }

}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context

{

    if (context == AVSEPlayerItemStatusContext) {

        AVPlayerStatus status = [change[NSKeyValueChangeNewKey] integerValue];

        BOOL enable = NO;

        switch (status) {

            case AVPlayerItemStatusUnknown:

                break;

            case AVPlayerItemStatusReadyToPlay:

                enable = YES;

                break;

            case AVPlayerItemStatusFailed:

                [self stopLoadingAnimationAndHandleError:[[[self player] currentItem] error]];

                break;

        }

        [[self playPauseButton] setEnabled:enable];

    } else if (context == AVSEPlayerLayerReadyForDisplay) {

        if ([change[NSKeyValueChangeNewKey] boolValue] == YES) {

            // The AVPlayerLayer is ready for display. Hide the loading spinner and show the video.

            [self stopLoadingAnimationAndHandleError:nil];

            [[self playerLayer] setHidden:NO];

        }

    } else {

        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];

    }

}

+ (NSSet *)keyPathsForValuesAffectingDuration

{

    return [NSSet setWithObjects:@"player.currentItem", @"player.currentItem.status", nil];

}

- (double)duration

{

    AVPlayerItem *playerItem = [[self player] currentItem];

    if ([playerItem status] == AVPlayerItemStatusReadyToPlay)

        return CMTimeGetSeconds([[playerItem asset] duration]);

    else

        return 0.f;

}

- (double)currentTime

{

    return CMTimeGetSeconds([[self player] currentTime]);

}

- (void)setCurrentTime:(double)time

{

    [[self player] seekToTime:CMTimeMakeWithSeconds(time, 1)];

}

- (IBAction)playPauseToggle:(id)sender

{

    if ([[self player] rate] != 1.f) {

        if ([self currentTime] == [self duration])

            [self setCurrentTime:0.f];

        [[self player] play];

    } else {

        [[self player] pause];

    }

}

- (void)reloadPlayerView

{

    // This method is called every time a tool has been applied to a composition

    // It reloads the player view with the updated composition

    // Create a new AVPlayerItem and make it our player's current item.

    self.videoComposition.animationTool = NULL;

    AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:self.composition];

    playerItem.videoComposition = self.videoComposition;

    playerItem.audioMix = self.audioMix;

    if(self.watermarkLayer) {

        self.watermarkLayer.position = CGPointMake([[self playerView] bounds].size.width/2, [[self playerView] bounds].size.height/2);

        [[[self playerView] layer] addSublayer:self.watermarkLayer];

    }

    [[self player] replaceCurrentItemWithPlayerItem:playerItem];

    // enable export

    [[self exportButton] setEnabled:YES];

}

#pragma mark - Utilities

- (void)updatePlayerLayerSize

{

    [self.playerLayer setFrame:[[[self playerView] layer] bounds]];

}

- (void)updateExportProgress:(NSTimer*)timer

{

    self.exportProgressView.progress = exportCommand.exportSession.progress;

}

- (CALayer*)copyWatermarkLayer:(CALayer*)inputLayer

{

    CALayer *exportWatermarkLayer = [CALayer layer];

    CATextLayer *titleLayer = [CATextLayer layer];

    CATextLayer *inputTextLayer = [inputLayer sublayers][0];

    titleLayer.string = inputTextLayer.string;

    titleLayer.foregroundColor = inputTextLayer.foregroundColor;

    titleLayer.font = inputTextLayer.font;

    titleLayer.shadowOpacity = inputTextLayer.shadowOpacity;

    titleLayer.alignmentMode = inputTextLayer.alignmentMode;

    titleLayer.bounds = inputTextLayer.bounds;

    [exportWatermarkLayer addSublayer:titleLayer];

    return exportWatermarkLayer;

}

- (void)exportWillBegin

{

    // Hide play until the export is complete

    [[self playPauseButton] setEnabled:NO];

    [[self exportProgressView] setHidden:NO];

    self.exportProgressView.progress = 0.0;

    [NSTimer scheduledTimerWithTimeInterval:0.05

                                     target:self

                                   selector:@selector(updateExportProgress:)

                                   userInfo:nil

                                    repeats:YES];

    // If Add watermark has been applied to the composition, create a video composition animation tool for export

    if(self.watermarkLayer) {

        CALayer *exportWatermarkLayer = [self copyWatermarkLayer:self.watermarkLayer];

        CALayer *parentLayer = [CALayer layer];

        CALayer *videoLayer = [CALayer layer];

        parentLayer.frame = CGRectMake(0, 0, self.videoComposition.renderSize.width, self.videoComposition.renderSize.height);

        videoLayer.frame = CGRectMake(0, 0, self.videoComposition.renderSize.width, self.videoComposition.renderSize.height);

        [parentLayer addSublayer:videoLayer];

        exportWatermarkLayer.position = CGPointMake(self.videoComposition.renderSize.width/2, self.videoComposition.renderSize.height/4);

        [parentLayer addSublayer:exportWatermarkLayer];

        self.videoComposition.animationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];

    }

}

- (void)exportDidEnd

{

    // Update UI after export is completed

    [[self playPauseButton] setEnabled:YES];

    [[self exportProgressView] setHidden:YES];

    [[self exportButton] setEnabled:NO];

}

- (void)editCommandCompletionNotificationReceiver:(NSNotification*) notification

{

    if ([[notification name] isEqualToString:AVSEEditCommandCompletionNotification]) {

        // Update the document's composition, video composition etc

        self.composition = [[notification object] mutableComposition];

        self.videoComposition = [[notification object] mutableVideoComposition];

        self.audioMix = [[notification object] mutableAudioMix];

        if([[notification object] watermarkLayer])

            self.watermarkLayer = [[notification object] watermarkLayer];

        dispatch_async( dispatch_get_main_queue(), ^{

            [self reloadPlayerView];

        });

    }

}

- (void)exportCommandCompletionNotificationReceiver:(NSNotification *)notification

{

    if ([[notification name] isEqualToString:AVSEExportCommandCompletionNotification]) {

        dispatch_async( dispatch_get_main_queue(), ^{

            [self exportDidEnd];

        });

    }

}

#pragma mark - Editing Tools

- (IBAction)edit:(id)sender

{

    int tag = [sender tag];

    // Disable the operation just selected

    [sender setEnabled:NO];

    AVSECommand *editCommand;

    switch (tag) {

        case kTrimIndex:

            editCommand = [[AVSETrimCommand alloc] initWithComposition:self.composition videoComposition:self.videoComposition audioMix:self.audioMix];

            break;

        case kRotateIndex:

            editCommand = [[AVSERotateCommand alloc] initWithComposition:self.composition videoComposition:self.videoComposition audioMix:self.audioMix];

            break;

        case kCropIndex:

            editCommand = [[AVSECropCommand alloc] initWithComposition:self.composition videoComposition:self.videoComposition audioMix:self.audioMix];

            break;

        case kAddMusicIndex:

            editCommand = [[AVSEAddMusicCommand alloc] initWithComposition:self.composition videoComposition:self.videoComposition audioMix:self.audioMix];

            break;

        case kAddWatermarkIndex:

            editCommand = [[AVSEAddWatermarkCommand alloc] initWithComposition:self.composition videoComposition:self.videoComposition audioMix:self.audioMix];

            break;

        default:

            break;

    }

    [editCommand performWithAsset:self.inputAsset];

}

- (IBAction)exportToMovie:(id)sender

{

    [self exportWillBegin];

    exportCommand = [[AVSEExportCommand alloc] initWithComposition:self.composition videoComposition:self.videoComposition audioMix:self.audioMix];

    [exportCommand performWithAsset:nil];

}

@end